The oldest ice ever found in North America shows that ancient permafrost withstood periods of warming, a new study says.
The oldest ice ever found in North America shows that ancient permafrost withstood periods of warming, a new study says.
Scientists fear that modern permafrost—soil that remains frozen in the polar regions—may melt and release potentially huge reservoirs of carbon that would speed global warming, scientists say. (See story.)
But the new study suggests that such a thaw could take much longer than previously believed, according to study leader Duane Froese, a geology professor at the University of Alberta in Edmonton, Canada.
Estimated to be at least 740,000 years old, the wedges of Canadian ice illustrate the longevity and resiliency of deeper permafrost during warmer climates of the past, they say.
